FIG. 1 is a plan view showing a conventional film-type sensor element assembly, and FIG. 2 is a plan view showing a conventional epoxy-type sensor element assembly.
As shown in FIG. 1, the film-type sensor element assembly can be used in narrow spaces because it is configured such that a sensor element 110 and lead frames 120 are formed into a film layer 140 by an insulating film to realize sensing functions.
However, this film-type sensor element assembly is problematic in that its form is not constant because the sensor element 110 is soldered to the thin lead frames.
Further, this film-type sensor element assembly is problematic in that it is extremely weak to external shocks, such as impact resistance, compressive strength and the like, because its structure is unstable due to the insufficient protection of the sensor element 110.
The epoxy-type sensor element assembly, shown in FIG. 2, is advantageous in that the diameter of lead wires 220 can be made small because a sensor element 210 is connected to the lead wires 220 coated with enamel 240 and then only the vicinity of the sensor element 210 is protected by an epoxy resin layer 230 to realize sensing functions.
However, this epoxy-type sensor element assembly is problematic in that, since the upper and lower sides of the sensor element 210 are soldered to the lead wires 220, the size of its head is determined by the diameter of the lead wires 220, so it is difficult to make the head small, and in that, since very thin lead wires must be used in order to make the head thin, its mechanical strength becomes low, so it is difficult to handle it, and its mass productivity is lowered.
Further, this epoxy-type sensor element assembly is problematic in that covered wires are stripped off or cut off by external mechanical shock because lead wires are thin.